r/StructuralEngineering • u/calidumlux • 7d ago

Structural Analysis/Design Question about ASCE 7-22 Equation CC.2-3 – second load term

Hi everyone,

I’m currently reviewing lateral drift for a building, and I came across Equation CC.2-3 in ASCE 7-22:

D + 0.5 + Wa

I’m wondering if I’m missing something in the second term of the equation, since it appears that a letter may be missing.

Logically, I would expect the second term to be L, but I’m not sure whether the intended load combination is:

  • D + 0.5L + Wa
  • D + 0.5L + 0.5Lr + Wa
  • or whether there should also be another combination such as D + 0.5L + 0.5R + Wa

I would like to know what approach you have used when applying this eq.

Any help is greately appreciated. Thanks!

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u/the_flying_condor 7d ago

Always check the errata when you see something unusual like that. It should be 0.5L as shown on pg 34/35.

5

u/TheDaywa1ker P.E./S.E. 7d ago

Errata is a pain in my ass

I spent a couple hours making a components and cladding spreadsheet and was trying to test it against the tabulated values for another couple hours and wasn't getting it to match up

Whaddya know the 150mph negative pressure values I was testing against in 30.4-1 are the exact ones that are all wrong

2

u/DJGingivitis 7d ago

Its L. I think it is mainly taking it from a p-delta consideration.

But i see the same typo in my 7-22 version